Immutable. This exact content is served forever at /api/v1/blob/2e5269c0c8290d48.
---
name: license-check
description: 'Package license analysis — detect copyleft conflicts against a permissive policy, surface AGPL / SSPL / GPL contaminants, output SPDX SBOM with per-package license findings. Use when auditing a release for license compliance, vetting a new dependency''s license, building an OSS-attribution document, or producing a customer-facing license disclosure.'
license: Apache-2.0
allowed-tools: Bash(vulnetix:*) Read Grep Glob
argument-hint: "[--policy permissive|copyleft-aware|strict]"
user-invocable: true
model: sonnet
metadata:
outputBudget: short
cooldown: per-session
---
# Vulnetix License Check Skill
## Use when
- Pre-release: confirm no copyleft contaminants in a permissive-licensed product.
- Vetting a new dep's license before adoption.
- Building an OSS attribution document (NOTICE file).
- Producing a customer-facing license disclosure.
- Quarterly compliance review with `--policy strict` to catch any non-allowlisted licenses.
## Don't use for
- Vulnerability scanning — use `vulnetix scan --sca`.
- License text retrieval — use the package manager directly (`npm view <pkg> license`).
## Conventions
Follows `skills/_lib/contract.md`. In short: use the `vulnetix_*` MCP tools when the agent has them and the CLI otherwise — both shape their own output, so there is no jq step any more. Independent calls go out as concurrent Bash tool calls in one message. One trailing suggestion, not a playbook. See the contract for surface selection, output style and memory writes.
## Step 1: Run license analysis
```bash
vulnetix license -o json-spdx > .vulnetix/licenses.${TIMESTAMP}.spdx.json
```
## Step 2: Apply policy
Default policy:
- **permissive**: flag GPL-*, AGPL-*, LGPL-* against MIT/Apache-2.0/BSD codebase
- **copyleft-aware**: flag AGPL-* and SSPL-1.0
- **strict**: flag any non-allowlisted license; allowlist = MIT, Apache-2.0, BSD-2/3-Clause, ISC, MPL-2.0
User can override via `--policy`. Accept user-supplied allowlist via `.vulnetix/license-policy.yaml` if present.
## Step 3: Render
```
| Package | Version | License | Policy verdict | Action |
```
Conflicts highlighted. Suggest replacement packages for blocked licenses (consult `vulnetix vdb packages search <name> --license <permitted>` if needed).
## Step 4: Compliance bundle hint
If `--bundle` flag provided, also output the file path so the `compliance-bundler` agent can pick it up.
## Memory update
`.vulnetix/licenses/<timestamp>.summary.yaml` with conflict counts.
## Edge cases & gotchas
- `--policy permissive` flags GPL-* / AGPL-* / LGPL-* against an MIT/Apache codebase; `--policy strict` allowlists only MIT, Apache-2.0, BSD-2/3-Clause, ISC, MPL-2.0.
- Custom allowlist via `.vulnetix/license-policy.yaml` overrides the built-in policy.
- License detection uses package metadata; dual-licensed packages (MIT OR Apache-2.0) are reported as the FIRST license unless the policy file says otherwise.
- SPDX expression parsing handles common patterns (MIT, Apache-2.0, BSD-3-Clause) but not custom non-SPDX strings like "see LICENSE file" — those flag as "Unknown".
- Transitive deps are included by default; pass `--direct-only` to scope to top-level packages.
- License findings DO NOT include legal review — flag them for legal counsel, do not auto-approve based on the skill output.